Comet (C/2011 L4) Panstarrs
Comet
C/2011 L4 (PANSTARRS), is a non-periodic comet discovered in June 2011,
that is expected to be visible to the naked eye when it is near
perihelion in March 2013. The comet was discovered using the Pan-STARRS
telescope located near the summit of Haleakala, on the island of Maui in
Hawaii.
Comet
C/2011 L4 had an apparent magnitude of 19 when it was discovered in
June 2011. By early May 2012, the comet had brightened to magnitude
13.5, and could be seen visually when using a large amateur telescope
from a dark site. As of October 2012, the coma (expanding tenuous dust
atmosphere) was estimated to be about 120 000 km in diameter. The comet
was spotted without optical aid on 7 February 2013 at a magnitude of ~6.
Comet
PANSTARRS will pass closest to Earth on 5 March 2013 at a distance of
1.09 au. It will come to perihelion (closest approach to the Sun) on 10
March 2013. Original estimates predicted the comet would brighten to
roughly apparent magnitude 0 (roughly the brightness of Alpha Centauri A
or Vega). An estimate in October 2012 predicted the comet might
brighten to magnitude -4 (roughly equivalent to Venus). In January 2013
there was a noticeable brightening slowdown that suggests the comet may
only brighten to magnitude +1. During February the brightness curve show
a further slowdown of Magnitude at perihelion around +2.5/+ 3.0.
Comet
C/2011 L4 probably took millions of years to come from the Oort cloud.
After leaving the planetary region of the Solar System, the
post-perihelion orbital period is estimated to be about 110 000 years.
| Date | Altitude at 7:00 pm IST | Azimuth at 7:00 pm IST | expected Magnitude (estimated) taken from MPC* | Comments |
| March 9 | 5 | 260 | 0.5 | |
| March 10 | 6 | 262 | 0.5 | |
| March 11 | 7 | 264 | 0.5 | |
| March 12 | 8 | 267 | 0.6 | |
| March 13 | 8.5 | 269 | 0.7 | Thin crescent moon will act as a guide to look for the Comet.It will be about 5 deg below the moon towards 7 o’clock position |
| March 14 | 9 | 272 | 0.9 | |
| March 15 | 10 | 274 | 1.1 | |
| March 16 | 10 | 277 | 1.3 | |
| March 17 | 10 | 279 | 1.5 |
* expected magnitude may vary drastically as the Comets are known to behave erratically as far as brightness is concerned.
Magnitude predictions and observation till Feb 20th
Best place to observe:
You should have clear western horizon with no light pollution. If your skyline in that direction is cluttered with trees, buildings, hills, whatever, chances are they’ll block your view of the comet.
